I have an older computer that was running Ubuntu 16.04. Whatever default video driver was installed worked with my video adapter. When I upgraded to 20.04 only the xfce desktop displays properly. I normally use Gnome.

My graphics card is older:

sudo lshw -C display
  *-display UNCLAIMED       
       description: VGA compatible controller
       product: G72 [GeForce 7200 GS / 7300 SE]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller bus_master cap_list
       configuration: latency=0
       resources: memory:e1000000-e1ffffff memory:d0000000-dfffffff memory:e0000000-e0ffffff memory:c0000-dffff

I downloaded what I thought was the appropriate install file for the driver: NVIDIA-Linux-x86_64-304.137.run

When I run this command I get an error. Here is the pertinent part of the error log:

   executing: 'cd ./kernel; make module SYSSRC=/lib/modules/5.4.0-96-generic/build SYSOUT=/lib/modules/5.4.0-96-generic/build'...
   NVIDIA: calling KBUILD...
   make -f ./scripts/Makefile.build obj=arch/x86/entry/syscalls all
   make -f ./scripts/Makefile.build obj=scripts/basic
   rm -f .tmp_quiet_recordmcount
   make -f ./scripts/Makefile.build obj=arch/x86/tools relocs
   make[3]: *** No rule to make target 'arch/x86/tools/relocs_32.c', needed by 'arch/x86/tools/relocs_32.o'.  Stop.
   make[2]: *** [arch/x86/Makefile:236: archscripts] Error 2
   NVIDIA: left KBUILD.
   nvidia.ko failed to build!
   make[1]: *** [Makefile:261: module] Error 1

I am new to trying to do something out of the standard graphical interface driven installs and configurations and am not a programmer.

When I ran the .run file above it did something to the nouveau driver so now everything is in very large font but I still have a graphical interface.

Can anyone guide me on how to install the nvidia driver for my graphics card? Am I missing something that should be installed to make this work?

Thanks so much in advance for any help. If there are other things I should post for people to help me, please let me know.